Surface active compounds



SURFACE ACTIVE COMPOUNDS William B. Hughes, Bartlesville, kl a., assignor to Cities Service Oil Company, Bartlesville, Okla., a corporation of Delaware No Drawing. Original application January 31, 1950, Se-

rial No. 141,598. Divided and this application October 25, 1952, Serial No. 316,939

1 Claim. (Cl. 260-307) This invention relates to surface active compounds, and more particularly to compounds efiective to cause a rapid and complete separation of the oil and oil phases of a water-in-oil emulsion. This is a division of my application S. N. 141,598 filed January 31, 1950, now Patent No. 2,638,451.

One of the most troublesome problems met with in crude oil production relates to the breaking of water-inoil emulsions formed in wells producing both water and brine. Unless these emulsions can be rapidly and completely broken, their oil content is lost. These emulsions will vary in properties from well to well and even from day to day in the same well, so that it may be necessary to use one demulsifier on one well, and another on an adjacent well, in order to secure optimum results.

It is an object of this invention to provide a series of compounds effective to rapidly resolve water-in-oil emulsions of the type commonly met with in crude oil production, to permit a complete recovery of the oil content of the emulsion.

It has been found that azolidines formed by the reaction of an aldehyde with a primary or secondary alkanol amine, neutralized with a propylated naphthalene sulfonic acid, are effective in breaking a wide variety of water-in-oil emulsions. These compositions will vary somewhat in properties depending upon the particular aldehyde or amine chosen as the starting material, so that it is possible, by proper selection of the aldehyde or amine, to tailor the composition to fit the individual emulsion which it is desired to break.

Among aldehydes which are suitable as starting materails for my new compositions may be mentioned formal-- dehyde, acetaldehyde, propionaldehyde, butyraldehydc, and higher aldehydes. I prefer, however, to use heptaldehyde, since i have found that the higher aldehydes give generally better results, and heptaldehyde is available commercially at a reasonable cost. Aldehydes higher than heptaldehyde may also be used, but are not preferred since their cost at the present time is such as to render them commercially unattractive.

As the amine, I prefer to use monoethanol amine or diethanol amine, since these amines are available commercially at low cost. Other alkanol amines, such as the propanol and butanol amines, and higher alkanol amines, may also be used.

,The propylated naphthalene sulfonic acid which I use as the neutralizing agent for my intermediate compounds may be prepared according to the directions given by Walker in U. S. Patent No. 1,873,165. The compound has the formula:

SOaH

in which Z is an isopropyl radical, and n is va whole number from 1 to 4.

Generally, in preparing my new demulsifiers, I prefer to mix the amine and aldehyde in approximately equimolar proportions, and then heat the mixture to force the reaction to completion and to drive the water formed in the reaction overhead. The reaction will proceed in accordance with the following general equation.

R being an alkanol radical or a hydrogen atom, and R being an alkyl radical or a hydrogen atom. The product is then neutralized to a methyl orange end point with propylated naphthalene sulfonic acid to give a product having the following generic formula:

in which Z is an isopropyl radical, and n is a Whole number from 1 to 4.

In order that those skilled in the art may more fully appreciate the nature of my invention and the manner of carrying it out, the following example is given.

' Example Heptaldehyde and diethanol amine were mixed in the proportion of 114 grams of heptaldehyde and 105 grams of diethanol amine. The mixture was thenheated at a temperature of about 150 C. until water ceased to evolve, the time necessary being about one hour, to yield a product having the formula CHr-CHI no-onT-oHT-N onebum-0H3 This product was then neutralized to a methyl orange end point with propylated naphthalene sulfonic acid.

The neutralized product may be used with success as a demulsifier in relatively pure form, but since it is rather viscous, and is diflicult to inject'into gathering lines during cold weather, it may be diluted to the desired viscosity with crude oil, other suitable hydrocarbon fractions, or other suitable solvents such as dichlorodiethyl ether,

chloronaphthalene, ketones, or alcohols in amounts ranging from about 10 to about per centof the total mixture. The product may also be used in combination with other commercial demulsifiers in order to improve their characteristics.

The various compositions described above are effective .to break a wide variety of emulsions, and are low in cost. While they are not uniformly successful in completely re- 4 my cqpganding application Serial No. 141,597, now Pat- References Cited inthe file of this patent enl UNITED STATES PATENTS Havmg now descnbed my mventlon, what is clalmed as ncw and useful is: 2,250,408 De Groote July 22, 1941 A d f th f l r 2,443,062 Abramovitch June 8, 1948 6 a 2,543,223 Blair Feb. 27, 1951 a 2,571,985 Carnes Oct. 16, 1951 -5 OTHER REFERENCES 3, H, 10 Bergmann: Chem. Reviews, v01. 53, pp. 309-13, 337 803 0-0 1953 N Chem. Abst., vol. 37, pp. 4395-96. H2 H2/ I \H HO--C--C B 0-0 Ce u 

